Community Forums

gmc70 · 08-27-2019, 08:07 AM

In the battery bay I have what appears to be a solenoid that is for the battery boost when you want to use house batteries for starting the engine. It is marked Trombetta 114-1211-020. The question is, it is warm, very warm. I am plug into a 30 amp out let but engine is not running and has been sitting. If I have DW turn the key on such as you would when go to start the MH and hit the boost switch it does click but can't hear a click when boost switch is released. What worries me is it being as warm as it is just sitting. Should I disconnect one of the positive terminals so house and chassis batteries cannot be connected together and replace? Any insight would be great. I just can't believe it should be that hot.

gmc70 · 08-27-2019, 09:06 AM

Found my answers. Finally found phone number for Trombetta and from what their tech dept. says they do run that hot. He said they can run anywhere from 160 to as high as 180 degrees. He says not to worry.

rmacdon61 · 08-27-2019, 09:50 AM

Sorry, but I find that response to your question suspect? It is a simple switch that normally sits in a neutral off position and only activated by a toggle switch to open the contact inside the solenoid?
I'd check the small terminals at the solenoid for power. Should be none. Then I'd remove one of the large terminals and check for voltage through the contacts or continuity between them. Simple check for peace of mind. If it is a closed circuit, replace, as it should be open at rest.

twinboat · 08-27-2019, 10:06 AM

Its not just the boost solenoid.

It serves double duty as your isolation/charge solenoid.

Anytime your engine is running and your chassis batteries are charging above 13.3 volts, it closes and also charges your house batteries.

On many MHs, it seems including your, it also works the opposite way. Your house battery charging system will maintain the chassis battery while on shore power.

While its doing its job, it has current running to the small wires to hold it engaged. That's what creates the heat.

If you were to disconnect shore power and had the engine off for a while, once the battery voltages dropped below the isolation control set point, the solenoid would disconnect and cool down.

gmc70 · 08-27-2019, 03:27 PM

Twinboat your comments are what the tech said. I thank everyone for the help.

YC1 · 08-30-2019, 07:58 PM

As usual Twinboat is spot on.

Put the following "battery,bird,monaco" into the little green google search box above for some great research information.

Totally normal for them to run too hot to touch. But they do fail and cause all kinds of headaches.

Not a bad item to replace every few years do to the failure histories and complaints on this forum.

fairway2002 · 08-30-2019, 08:38 PM

Quote:

Originally Posted by twinboat

Its not just the boost solenoid.

It serves double duty as your isolation/charge solenoid.

Anytime your engine is running and your chassis batteries are charging above 13.3 volts, it closes and also charges your house batteries.

On many MHs, it seems including your, it also works the opposite way. Your house battery charging system will maintain the chassis battery while on shore power.

While its doing its job, it has current running to the small wires to hold it engaged. That's what creates the heat.

If you were to disconnect shore power and had the engine off for a while, once the battery voltages dropped below the isolation control set point, the solenoid would disconnect and cool down.

Thanks. I am now smarter. great info